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Lanthanides

Praseodymium

A rare earth that gives strong magnets and green glass.

Atomic #59Mass140.91Blockf-blockPeriod6Group
Pr59 · 140.91
3D Atom Explorer

Inside the Praseodymium atom

Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Praseodymium atom step by step.

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Electron configuration

[Xe] 4f3 6s2

A neutral Praseodymium atom has 59 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.

Shell distribution

Shell 12 e⁻Shell 28 e⁻Shell 318 e⁻Shell 421 e⁻Shell 58 e⁻Shell 62 e⁻

Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.

Properties

Physical & atomic properties

State (room temp)
Solid
Melting point
1208 K (935 °C)
Boiling point
3793 K (3520 °C)
Density
6.773 g/cm³
Electronegativity
1.13 Pauling
Atomic radius
185 pm
1st ionization energy
527 kJ/mol
Category
Lanthanides
History

Discovery & naming

Discovered
1885
Discovered by
Carl Auer von Welsbach
Origin of name
Greek 'prasios didymos', meaning green twin.

Notable uses

Powerful magnets, aircraft engines, and coloured glass.

Cosmic origin

Where Praseodymium comes from

Stellar fusion and dying stars

An important source is slow neutron capture in dying low-mass stars.

Simplified origin map — many elements form through more than one astrophysical pathway.

Summary

Atomic number
59
Atomic mass
140.91
Category
Lanthanides
Group · Period
— · 6
Block
f-block
Shells
2 · 8 · 18 · 21 · 8 · 2